The chosen condition is: being wrongly convicted of a serious crime.
Gregor was judged and isolated because his appearance did not show what he really was anymore. His own family failed to keep on thinking of him as a human being, their own flesh and blood, a being capable of reasoning and feelings just like themselves.
The same might be observed if a person were to be convicted of a crime they haven't committed. In general, society has a tendency to distrust people who have made serious mistakes, or who seem to have made them. They fail to see the person behind what they believe to be true, thus failing to give them a chance and a helping hand.
It is currently possible to watch an unfolding situation regarding a famous crime. Steven Avery has become the object of much discussion after the series Making a Murderer presented arguments and, more recently, even proof of his innocence. However, people who have chosen to believe he is guilty are not willing to reconsider. If he ever gets freed, Avery knows he'll have to find somewhere else to live, for his chances of surviving at the community where he has grown up are very low.
The case above is merely an example, and is yet to be closed. Be it Avery or someone else, the stigma the person has to carry is a heavy burden. The lack of trust prevents the person from finding a job, becoming an active member of the community, and, sometimes, it causes estrangement from their own families. People are quick to judge the mistakes - or the appearance - of others and slow to forgive or believe them.
Note: if you dislike the example given, feel free to remove it from the text. It may be a bit polemic to mention this case.